PURPOSE: To obtain an artificial graphitic roll material preventing the cracking of the surface of a silicon steel plate by forming the sleeve of the roll with artificial graphite holding pores having specified properties and by connecting all the pores.
CONSTITUTION: A roll material is obtd. by forming the sleeve of the roll with artificial graphite holding pores all of which have been connected. Each of the pores has a shape similar to a circle or an ellipse, ≥60% of all the pores have ≤4 ratio between the maximum width of the pore and the minimum width passing through the center, and the maximum width of the pores is adjusted to ≤50μm. A filler having ≤ about 30μm average particle size and ≥ about 85% fixed carbon content is used. Particles having ≥ about 100μm particle size are not contained in the filler, and ≥ about 50% of the filler is composed of particles having ≤ about 40μm particle size. A binder having about 60W70% fixed carbon content and a binder having about 20W30% fixed carbon content are used at the same time. The filler and the binders are kneaded with about 10W 20% polar org. solvent, kept at different temps. for a fixed time, crushed, immediately subjected to isostatic pressing, and sintered in an inert gaseous atmosphere.
HOSHINA KATSUMI
OOKAWA MASAYUKI
UESHIMA NOBUYUKI
SASAKI YASUMI
